Mindfulness is certainly a hot topic and it has been extensively covered on the Mental Elf, for example in André Tomlin’s summary of mindfulness evidence, which coincided with Mental Health Awareness Week (#MHAW15) last year.

600 mindfulness RCTs and 250 mindfulness systematic reviews and meta-analyses were published worldwide in 2014.

In a recent meta-analysis published in Annals of Family Medicine, Demarzo and colleagues (Demarzo et al., 2015) set to investigate for the first time the application and effectiveness of mindfulness-based interventions (MBIs) in primary care patients.

This meta-analysis claims to be the first evaluating mindfulness-based interventions in primary care.

Methods

The authors included randomised controlled trials (RCTs) of MBIs addressed to patients recruited in primary care, and in which the mindfulness intervention was compared to a control condition.

Primary care services were defined as those providing coordinated, accessible, comprehensive, and long-term health care services, as well as practices in the context of the family or community.

Participants had to be adults, but there were no restrictions about existing conditions.

Mindfulness-based interventions (MBIs) were defined as interventions listing mindfulness as a key component, including mindfulness-based stress reduction (MBSR) and mindfulness-based cognitive therapy (MBCT). However, blended or mixed interventions, which included a mindfulness component, like acceptance and commitment therapy or dialectical behavioural therapy, were excluded.

Eligible control conditions included treatment as usual, waiting list, or any active comparison condition, like other psychosocial interventions, pharmacotherapy, or placebo.

The outcomes considered were clinical and patient reported outcomes from any self-report instrument designed to measure mindfulness or any other variable related to patient health.

Risk of bias was assessed with the tool developed by the Cochrane Collaboration, with studies meeting 3 or more criteria being considered as high quality, and the ones meeting fewer than 3 as low quality. The authors also assessed the quality of the interventions in 3 areas: use of a treatment manual, provision of therapy by specifically trained therapists and the presence of treatment integrity checks during the study.

Effect sizes (ESs) indicated the differences between the two groups at post-test or follow up and were assessed with the indicator Hedges g. (.20, .50 and .80 correspond to small, moderate and respectively large ES).

Results

Six RCTs met the inclusion criteria and were included in the analysis.

Three of the studies used a MBSR-like programme and 3 an MBCT-like one. All included face to face interventions. Participants ages ranged from 43.6 to 69.8 years and their clinical conditions consisted of chronic musculoskeletal pain, mood disturbance, chronic stress, chronic illness and medically unexplained symptoms. The control conditions were waiting list, usual care, massage or spirituality programs.

In terms of risk of bias, two of the included RCTs could be categorised as high quality, with the other four being low quality.

MBIs also significantly improved mental health (g= 56), but there was high heterogeneity for this outcome (I2 = 78%).

There was a significant effect of MBIs for improving quality of life (g= 29), with low heterogeneity.

Though seriously underpowered, subgroup comparisons indicated that, predictably, comparisons with passive controls resulted in significantly higher ESs than those with active controls (p= .01). Differences between MBSR and MCBT interventions were not significant. There were also differences according to the time point of the outcome measures (post-test, follow-up of under 6 months, follow-up of over 6 months), with longer follow-up leading to a smaller and non-significant improvement (but there were only 2 studies in this category, making the result unreliable).

The authors searched far and wide but only found a meagre 6 RCTs of mindfulness-based interventions in primary care.

Conclusions

The authors concluded that:

We found 6 RCTs of MBIs conducted in primary care, which is low compared with the number conducted in secondary or tertiary care. This disparity may be due to the fact that research in primary care is still comparatively less developed.

They go on to state that:

Our analysis showed a moderate effect size in favor of MBIs in primary care for mental health–related outcomes and quality of life, with a low risk of publication bias and a moderate level of heterogeneity.

They also emphasised that:

This meta-analysis is the first to address the efficacy of MBIs in primary care patients. There is still insufficient evidence to draw a conclusion about the effects of mindfulness interventions in this setting.

There’s not enough evidence to draw any conclusions about the effectiveness of mindfulness-based interventions in primary care.

Limitations

The most important limitation is that the number of included trialsis very small and the authors did not conduct a power analysis to verify how many trials with what average number of participants would have been needed to evidence an effect. As such, the effect size estimations are not very reliable and limited in terms of practical implications.

Not only is the number of included RCTs small, but they are also very heterogeneous in terms of the populations being studied, the outcomes assessed, the time points for assessment and the type of control groups. This is also evident statistically (moderate or high I2) for some comparisons, but even for the comparisons where estimations of heterogeneity are not visibly high, given the reduced number of studies, we should still maintain skepticism about the reliability of the effect size estimations.

Consequently, all subgroup comparisons are underpowered and their results not really interpretable.

The small number of included trials and their heterogeneity make the effect size estimations quite uncertain.

Summary

While the limited number of eligible studies and their high degree of heterogeneity (patients targeted, outcomes and time points considered) preclude us from drawing any reliable conclusions about the actual effectiveness of mindfulness-based interventions in primary care settings, this meta-analysis does serve the important role of highlighting how little research on this topic there actually is.

Consequently, the take home message is not so much that MBIs could be effective in primary care settings, but rather that there is a dearth of actual randomised trials on these interventions in this context. As highlighted in a Mental Elf recent blog, clinical practice and policy recommendations seem to be changing quicker and out of sync with actual outcome research.

Mindfulness is popular, but there remains a lack of evidence to support the use of mindfulness-based interventions in primary care.

Disclosure

I collaborate on a number of professional projects with one of the authors of this meta-analysis (Pim Cuijpers), but had no involvement in this specific study.

Ioana is Associate Professor at Babes-Bolyai University, Cluj-Napoca and a Research Fellow at the University of Pisa, Italy. She holds a masters degree in Clinical Psychology, a Ph.D. in Psychology, and is a board certified cognitive-behavioral therapist. Her main research interests include critically appraising the efficiency and mechanisms of action of psychotherapy interventions.

Please can researchers stop doing meta-analyses of complex psychological interventions in diverse patients populations. Of course you can’t draw any reliable conclusions, because the analysis is meaningless. There is so much clinical heterogeneity that the studies should not have been combined in the first place. But that is not to say that the studies themselves are not valuable, or that the interventions are not valuable – just that they should be considered on their own merits, within the context of the patient populations in which they were done.

In summary, this meta-analysis is meaningless for the following reasons:
1. The outcome measure is a summary measure of summary measures of summary measures. Worse, the original outcome measures weren’t even necessarily measuring the same thing.
2. Different patient populations and conditions were studied in each trial. OK, they were all done in a primary care setting, but it’s a bit like combining trials of aspirin for headache and aspirin for heart disease.
3. Different control groups were used. Some may have included nocebos (wait list) or active placebos.
4. “More RCTs are needed.” With the best will in the world, an RCT of a complex intervention like psychotherapy, even a perfectly conducted one, is not going to tell you whether that intervention will work in a general primary care setting. The more controlled an RCT is, the further away it is from replicating what actually happens in the field. Efficacy is not the same as effectiveness.

So is there any point? Just give patients a wide choice of therapies. Trying to find the one golden therapy that suits everyone is a waste of time. We already know that pretty much every therapy on offer helps about a third of patients. Different people may require different strategies. Some will prefer mindfulness, others will prefer CBT, others may want a combination, but you can’t tell until you try.